Distilling petroleum.



W. C. KOEHLER & L. LINK. DISTILLING PETROLEUM. APPLICATION FILED JULY 5,1910. RENEWED JUNE 26, 1913.

LUSLUJL 6. Patented Jan. 13, 1914.

" awucwtom MM 6. fad/, 2 ii M dam/{ 7 1 I MM. W I j firm-mm;

I l I I 1 l I l l I I SAT #1 l T TENT OFFICE.

WILLIAIVI C. KOEHLER AND LUDWIG LINK, F ELIZABETH, NEIJV JERSEY,ASSIGNORS TO STANDARD OIL COMPANY, OF- BAYONNE, NEW JERSEY, ACORPORATION OF NEW JERSEY.

weenie.

Application filed July 5, 1910, Serial No. 570,373.

To all whom it may concern:

Be it known that we, IVILLIAM G. KonnLnn and LUDWIG LINK, both citizensof the United States, residing at Elizabeth, in the county of Union andState of New Jersey. have invented certain new and useful Improvementsin Distilling Petroleum, of which the following is aspecification.

This invention relates more particularly to the distillation of thelubricant or lubricant and wax yielding fraction of crude petroleum attemperatures above (350 F. and with protection of the vapors againstundue cooling before they pass over to be condensed as distillate, so asthereby to obtain distillate which shall contain the decomposable butundecomposed (or only slightly decomposed) hydrocarbons of said fractionand shall consequently be well suited for use as a lubricant and waxyielding material where the crude petroleum yields paraffin wax, or as-alubricant stock simply where it does not; for it is well known that thesuitability of distillate as such material or stock is impaired when itsdecomposable hydrocarbons are cracked (decomposed) to more than a slightextent (if at all) and that undue cooling of the vapors before they passover to be condensed as distillate results in objectionable cracking.But each of the improvements composing the invention is intended to besecured for all the uses to which it can be applied with or withoutmodification. I-Ieretofore'in thus distilling said fraction much of thedistillate has had to be rerun before it could be satisfactorily pressedfor paraffin wax in the case of distillate from wax yielding petroleumor be given the customary sulfuric acid and alkali treatment in the caseof distillate from petroleum having an asphaltic base. In the formercase gummy matters have been present which clog the filter press and soprevent the pressing of the distillate at least with facility; and inthe latter case asphaltic matters have been present which in thecustomary treatment with sulfuric acid and alkali unite with the alkaliin the form of an emulsion that will not separate on standing. Indistilling, for example, the petroleum from the Illinois and Kansasfields (a petroleum which yields paraffin wax) the best results in ourexperience have heretofore been the production in the crude oil run(along with lighter distillate) of about twenty per cent. of distil-Specification of Letters Patent.

Patented J an. 13, 191d.

Renewed June 26, 1913. Serial No. 775,964.

late available as lubricant and wax yielding material without furtherdistillation and about eight and a half per cent. of distillate (termedslop) which must first be rerun. In rerunning nearly a fourth as muchslop is again produced, making the total amount of distillate to bererun constantly about ten and a half per cent. of this kind of crudeoil. Vi e have discovered that it is possible materially to reduce thepercentage of slop produced in the crude oil run in distilling thelubricant or lubricant and wax yielding fraction of petroleum asaforesaid; and we thus are able to effect a substantial saving inexpense of working as compared with any previous process for performingsuch distillation with which we are acquainted; while the loss bydecomposition may even be less than heretofore, when the decompositionin rerunning is taken into account. IVe have found (first, as webelieve) that much of the vapors of lubricant or lubricant and waxyielding character which are accompanied by gummy or asphaltic mattersin their passage from the still can be freed from such matters beforesaid vapors are condensed as dis tillate by a suitably extended travelof the suitably cooled vapors in contact with oppositely flowingcondensate in connection with a return of said condensate to the oil indistillation, without. countervailing loss by decomposition ofhydrocarbons or otherwise.

Conditions of cooling and travel which we have found efficient will behereinafter set forth by way of example. It is only essential, first,that the cooling should be sufficient to effect the condensation of thegummy or asphaltic matters and not so far below the contemporaneoustemperatures of the oil in distillation that the advantage otherwise ofthe new or improved process over the prior state'of the art would bemore than offset by the detrimental effects of increased decompositionand evaporation in the still which would result from excessive coolingof the vapors; and, second, that the travel of the suitably cooledvapors in contact with oppositely flowing condensate on its way back tothe oil in distillation should be sufiicient to free said vaporspractically from said gummy or asphaltic matters. After the vapors havepassed over to be condensed as distillate, they are subjected tofractional condensation with flow of vapors and condensate in oppositedirections in contact with each other in order to obtain distillate oflubricant or lubricant and wax yielding character as free as may be frommore volatile hydrocarbons; and the facility or difficulty with whichthe so obtained distillate can be pressed for wax so thatpressingwithout rerunning would or would not be preferable to rerunningand subsequent pressing (in the case of wax yielding petroleum) and theability or inability of the distillate to separate on standing from thealkali of the customary sulfuric acid and alkali treatment when it issubjected thereto (in case of other petroleum) will indicate whether it.has or has not beenmade practically free from gummy or asphalticmatters. If not thus free therefrom the vapors may be made to travellonger in contact with the oppositely flowing condensate with or withoutadditional cooling as may be considered necessary or expedient. It isconsidered best to reduce the volume of this condensate as much as isconsistent with the practical freedom of the vapors from said gummy orasphaltic matters when they pass over to be condensed as distillate. Thedistillation of the said fraction as a whole is best performed ashereinafter described; and the apparatus, which is hereinafterdescribed, is best employed for the purpose.

Figure 1 of the accompanying drawings is a plan View of said apparatus;Fig. 2 is an elevation of the same, partly in vertical v longitudinalsection; and Fig. 3 is a detail view of one of a number of small reliefvalves forming part of said apparatus.

The fire heated still a,.-say in the form of a horizontal cylinder andof about a thousand barrels capacity, more or less, suitably jacketed toprevent undue cooling of the vapors before they leave the vapor space,is provided with a valved charging line b, a valved run back 0, and avalved steaming out line d. It is connected by a vapor pipe e (saytwelve inches in internal diameter and about twenty five feet long) withthe lower part of chamber f provided with a heat retaining jacket andbeing, say, about seven feet in internal diameter and about eight feethigh. The vapor pipe e has a short upright portion at its inlet end; andit thence descends toward its outlet end. Within chamber 7 are bafliesin'the form of cobble stones 9 (say from about four to about eightinches in diameter) loosely piled together to a depth. say, of aboutfour feet and resting upon the grating it above the outlet end of thevapor pipe e.

Above the chamber 1 is an air cooled tubular condenser composed of, say,sixty pipes 2', each about eleven feet in length and about four inchesin external diameter, set in an inclined position between the tubesheet]: at top of chamber 1 and the annular header Z. As shown in Fig. 3at the upper-end of each pipe 71 is a light valve m (say about thirtythree ounces in weight) with an opening '27, therein of smaller diameterthan the inside of the pipe 2' (say an opening of about an inch and aquarter in diameter) The restricted openings 12, tend to equalize thecurrents in the several pipes 2'; and one or more of the valves m wouldrise and release the pressure in said pipes i if it should at any timebecome excessive.

The pipes i are inclosed in a casing 72 which at the top fits around theheader Z and which has inlet openings 9 at the bot tom for inflow of airfrom the surrounding atmosphere. Each inlet is provided with a valve 1";which can be opened to the extent desired, or can be closed. The casingis open on top through the annular header Z, but closed at bottom exceptfor the valved inlets g.

From the interior of header Z a vapor pipe 8 leads to the bottom of anair cooledtubular condenser 25. From the top of this latter a vapor pipeu connects with the water cooled condenser '20 formed ofa single pipewhich is immersed in the water of tank a; and whose upperend only isrepresented, the rest of it being broken away for simplicity ofillustration. The pipes 5, 8, 9 and 10- are similarly represented. Thetank 00 is supplied with water by pipe 3 and provided with an overflow2.

Between the chamber f and the pipes 71 are means (in the form as shownof a saucer 2 and a valved outlet 3 from said saucer) forenabling (atthe will of the operator) the condensate from pipes i to be supplied tochamber f or to be otherwise disposed of. As shown, the saucer outlet 3connects through a trap 4 with a-distillate draw off 5, which isimmersed in the water of tank a: for cooling.

The chamber f has a liquid outlet 6, which is connected with said trap 4and distillate draw ofi' 5, also with the run back 0, also with asecond-valved distillate draw off 8 which is not immersed in the waterof tank a; and is consequently of higher temperature than pipe 5, and(if so desired) also with a valved draw off 9 (indicated in dot-tedlines) which is suitably trapped and immersed in the water of tank 2:.In outlet 6 between the trap and the draw Oils 8 and 9 is a valve 7.

Llhe condenser t has its liquid outlet connected with a trapped andvalved draw off 10 immersed in the water of tank at. As shown, saidoutlet is also connected with the run back 0, namely, by a valved branchpipe 11.

The vapors from still a, after cooling to a certain extent in vapor pipee, enter the lower part of chamber f and, after passing up. between thestones g, proceed thence through pipes z, header Z, vapor pipe 8, air

cooled condenser t, vapor pipe to and water L cooled condenser 4.0; Inthis last all but the non-co-ndensable gases (and very lightest I in"liquid hydrocarbons) are reduced to the liquid state, 'the uncondensedgases (and vapors) passing off in :the known way, to.

be disposed of as may be desired.

- fcrred) either to the run back or to the draw oit 5, to thedraw off 8of higher temperature, or to the draw off 9, should this last beprovided.

By opening and closing the proper valves the condensate'from the pipesican be allowed to fall into the chamber f, thence to.

, distillation above 650 F.

flow away through one of the pipes con-* nected with pipe 6; or it canbe diverted by saucer outlet 3 direct to the distillate draw Thecondensate from condenser is drawn off through pipe 10; or, if desired(by changing the through the back 0. The condensate from condenser w isdrawn 01f from the outlet thereof in ordii narily at least asufficiently cool state.

branch pipe 11 to the run} In distilling the lubricant and wax yield lingfraction of crude petroleum, say from the Illinois and Kansas fields,such petio leum can be deprived in any known or suit able way of itsmore volatile fractions, representing about 58 per cent. of-the crudeoil '1 by volume; and the so obtained residual oil (representing about42 per cent. of the crude oil) can then be charged into the still a; butit is more advantageous'to supply the still a with the crude oil itself;or with an undistilled residual oil therefrom containin more or less ofsaid more volatile fractio ns in addition to the lubricant and waxyielding fraction. In the latter cases thereis no interruption to thedistillation when said more volatile fractions have been removed; butwhereas in removing them the run back 0 is open and the saucer outlet 3closed (draw offs 8 and 9 and valve 7 also closed) when they have beenremoved the run back 0 is closedand the valve 7 is opened (saucer outlet3 and draw ofi's 8 and 9 remaining closed). In the former case the stillfor distillation of the lubricant and wax yielding fraction may bebrought in either with the run back 0 open and valve 7 closed orconversely (saucer outlet 3 and draw ods 8 and 9 being closed). In anycase d 1st1llat1on of the lubricant and wax yielding fraction is in duecourse carried on with the 011 in in temperature and with the run back 0closed. valve 7 being open and saucer outlet 3 and draw-offs 8 and 9being closed; so that all the condensateformed after the vapors leavethe ordivalves), it can be delivered i maining closed);

nary vapor space of the still and before they leave the header 1,exceptythe small amount formed in the upright part of a vapor plpe e, iscollected as distillate through the pipe 6 and draw of]? 5; while thewellrectified vapors pass on by pipe 8 to the condenser t. In thislatter further condensation takes place; and the condensate therefrom iscollected as distillate through the draw ofi' 10. The uncondensed vaporspass 75 by pipe u to condenser w; from which the condensate is collectedas distillate; while.

the gases and any uncondensed vapors pass off to be burnt under thestill or to be. otherwise disposed of.

Satisfacto-ry lubricant and wax yielding dlstillate should be receivedfrom draw 911' 5 while the gravities of samples taken from the stream atitsoutlet end are changing from about 31 4 10 '13. at 60 F. (which 151about the gravity of the--first distillate so received whichbelongs tothisffraction of the crude oil under consideration) toabout 26 B. Theviscosities of these samples should range from about 65 secondsto'ab'out "1,08

seconds measured at F. by Saybolts Universal Viscosimeter. They shouldfirst I exhibit cloudiness, due to solidification of the paraflin waxtherein, at temperatures ranging from 56 should range in temperaturefrom. about 698 F. to about 745. F. The vapors pass over to be condensedas distillate almost as 10 F. to about 55 tion during this period maywell occupy about 12 hours,

the crude oil, about 20 per cent. being received by the draw off 5 andthe remainder from the draw off 10 and condenser 20.

When the distillate from draw cit 5 exhibits a gravity of about 26 B. itwould become unsatisfactory (according to our experience with saldIllinois and Kansas 011) if the distillation were continued in the samemanner and would have to be-rerun before it could be'pressed, at leastwith equal ad- To avoid the formation of this distillate (or slop) assoon as (or just before the lead him to expect vantage. unsatisfactoryit malges' its appearance workers experience may it) thesaucer outlet 3is opened; so that only condensate from the pipes i is collected asdistillate through draw of? og and the run back 0 is also opened, thepipe 6 being closed at valve 7 (and draw ofYsS-and 9 re- F. to 78 F;when the samples are gradually reduced to sufliciently low temperatures.The oil in distillation from 620 F. to about 105 F. below the oil indistillation. The distillaand the total distillate collected equal about27 per cent. by volume of 110 so that the condensate 68 F. and about 76F. Theoil in distillation should range in temperature from about 745 F.to about 795 F. The vapors pass 'over to be condensed as distillate onlywhen they have reached the upper partof chamber f; so that subsequentlyformed condensate can be received in the saucer 2; and

- centby volume of the crude oil, about 7% when they thus pass over theyshould range in temperature from about 67 F. to about 685 F. or fromabout 71 F. to about 115 .F. below the oil in distillation. Thedistillation with saucer outlet 3 and run back 0 open may well occupyabout 6 hours, and the total distillate collected equal about 9 per percent. being received through saucer outlet 3 and draw off 5' and about1% per cent. by drawofif 10 and condenser w.

Whensth'e distillate from draw ofi 5 exhibits. a -\gravity'of about 24B., in order to enable the stills contents to be dried out or coked,.the run back 0 and the saucer outlet 3 are both of them closed and thevalve 7 inrpipe 6 is openedyso that the vapors pass over to be condensedas distillate .just after they leave the ordinary vapor space of thestill. When the distillate becomes too thick atthe temperature of thedraw off 5, the

valve 7 is closed and the draw off 8 is opened for the passage throlihit of the'distillate.

The distillation after c osure' of saucer outlet 3 and run back a mayoccupy'about three hours and yield a total distillate equal to about 2per cent. of the crude oil. About half of it would be received throughthe draw offs 5 and 8 (in succession) and about half from the draw off10 and condenser w (concurrently until the flow from one of themceases). The distillate which at this period would be received throughthe draw off 5 would (in our experience) be unsatisfactory withoutrerunning. That which would be received through the draw ofl 8 would bewax tailings.

The coke and loss during an uninterrupted distillation of all fractionsof a charge of crude oil may represent about four per cent. by v0lume ofthe'crude oil.

In distilling the lubricant or lubricant and wax yielding fraction thevapors which are cooled in pipes 71 should have a temperature between4.00 F. and 600 F. when they leave the header Z. By setting the valves rthis cooling in pipes i can be regulated m' accordance with theindications furnished by the distillate from the drawofl's 5 and 10, soas to obtain distillate of lubricant and Wax yielding character suitablyfree from more volatile hydrocarbons. These latter pass on to thecondensers t w and are collected as distillate as long as condensateruns therefrom.

The particular figures which have been given are by way of example, inorder' the better to enable those skilled the art to practise theinvention, and not as restricting the invention thereto; andmodifications in process, apparatus or both can be -made indefinitely solong as the substance is taken of any one or more of the hereinafterWritten claims.

In drying out or coking the contents of the still, the run back 0 can beclosed and the part thereof. So, too, it is not necessary that all thelighter and all the heavy end of said fraction'should be distilled asherein above described therefor, respectively; but any substantial andappropriate part of either of them may beso distilled. In fact, asmentioned, by reason of the difliculty (or practical impossibility) ofdrying out or coking the stills contents with run back 0 open, it isdesirable to stop the return of condensate from chamber 7 before all theheavy end of the oil is received. All or any substantial and appropriatepart of the condensate formed in the descending part of yapor pipe 6 andin chamber 7 in the distillation of said heavy end when the sauceroutlet 3 is open can be returned to the liquid oil in distillation;although it is designed that all of it should be soreturned. It is alsodesigned that after the condensation of vapors as distillate in pipes i'(or in vapor pipe e, chamber f and pipes 2', according to the case) all.

the remaining vapors should, as far as possible, be condensed incondensers t and w; but,

if desired, part only of them may be socon= densed.

In the hereinafter written claims, there- 'fore, the respective recitalsare to be con strued to apply to all, or to any substantial andappropriate part, of the therein specified fluid or fluids.

It is believed that the general designation of lubricant or lubricantand wax yielding fraction of crude petroleum designates the partintended sutficiently for all the purposes of this specification; but,should greater preclslon be desired, said fraction of mam 'a charge ofthe same under atmospheric pressure with gradual rise oftemperature andintroduction into the liquid oil of free steam .in suflicient volume toprevent cracking,

samples of distillate taken in succession at "the outlet of .thecustomary water cooled condenser exhibit either a viscosity as high as65seconds at 100 F. by Saybolts Unlversal Viscosimeter or a cloud at atemperature,

I as high at 50 F. (whichever characteristic first appears). Whenanother charge of crude petroleum of the same kind is distilled in anyknown or suitable way until the undis tilled residue represents thispercentage of the crude oil, such residual oilv can be taken to containsubstantially the entire lubricant or lubricant and wax yieldingfractionof the crude oil without any portion of another fraction.

In order to secure concordant results, the assays must always beperformed under identical conditions; and they may well be performed byusing such a laboratory apparatus as is shown in out No. 1286 in thecatalogue for 1908 of E. H. Sargent & Company, of 145 Lake Street,Chicago,1llinois, Said apparatus has a copper still of cheese boxformheated by a gas flame underneath;

and it is provided with means for introduc-' ing free steam into theliquid oil in the still. A still with a charging capacity of about tenliters would be large enough; and it should receive a charge about equalto its capacity. In the distillation the heat may be so regulated thathydrocarbon distillate is received from the condenser at the uni, formrate of about fifteen per cent. by volume per hour of the charge ofcrude oil; and the free steam supply may be so regulated that the streamfrom the condenser contains water of condensation equal in volume tofrom a third to a half of the hydrocarbon distillate. The ,steam may bedry and saturated; or it may be slightly superheated The samples ofdistillate may be two per cent. by volume of the original charge ofcrude petroleum.

Some petroleum may be of such peculiar character that all of itslubricant or lubricant andwax yielding fraction would be distilled withthe separation herein above described as applied to the heavy end ofsaid fraction; and in'such case, of course, the heavy end (no less thanthe lighter end) of its said fraction would be distilled with suchseparation. The recital that vapors of the heavy end of said fractionare subjected to certain operations does not of itself require that thevapors of said heavy end only should be subjected thereto.

Advantage over the prior state of the art is efiected by a suitablyextended travel of the suitably cooled vapors of said heavy end incontact successively with two lots of oppositely flowing condensate,separately col-- lected as distillate, without the described return ofcondensate to the oil .in distillation. The conditions of cooling andtravel in vapor pipe 6 and chamber f as described are considered. bestfor the first of the two separations. It is only essential thereto thatsaid cooling should be suflicient to efiect the condensation of thegummy or asphaltic .matters and not as much as to condense practicallyall of the lubricant or lubricant and wax yielding hydrocarbons, andthat the extent of the travel should sufiice for the vapors passing onto be practically free from said gummy or asphaltic matters. Theconditions of cooling and travel in pipes 2' as described are consideredbest for the .tillate received by draw off 9 should become too thick toflow properly at the temperature of the latter. The draw oil 8 wouldthen be opened; the draw off 9 would be closed, saucer outlet 3remaining open and the run back 0 remaining closed; and distillationwould ,be' continued until the. contents of the still should becomedried out or coked to the desired extent. lVhile, however, to work inthis way would be an advance over the prior state of the art and is,therefore, included in the invention, it is inferior to the working-withthedescribed return of condensate, which latter working moreparticularly constitutes the invention. For example, without suchreturn, the lubricant and wax yielding fraction of Illinois and Kansaspetroleum has been distilled bv us with the production in the crude oilruh of slop equal to about three and a half per cent/by volume of thecrude oil as against about e1ght and a half per cent. by the best priorpractice known to us and about one per cent. by our working with thedescribed return of condensate. In the hereinafter written claims theword withdrawing as apphedto-a condensate includes a collection asdistillate or a return to the oil in distillation, whichever dispositionofthe condensate may be adopted, said collection and said return belngconsidered each of them a mode of withdrawal of the condensate.

" In the foregoing description and the accompanying drawings we haveexhibited our invention in connection with matters which we are informedand believe "by John .W. Van Dyke and William M. Irish, both of-Philadelphia, Pennsylvania, and which are described and claimed by themin their application of October 4, 1909, No. 520,937 and in divisionsthereof. The invention of said Van Dyke and Irish is, of'course, not

claimed in whole or in part by us..

We claim as our invention or discovery: l. The process of distillingpetroleumina form which contains the defined lubricant (or lubricant andwax yielding) fraction of the crude petroleum, by heating suchundistilled petroleum (eventually at least) to the high temperatures(above 650 F.) necessary to distil the heavy end'of said fraction,

: subjecting the vapors evolved from said heavy end and protectedagainst undue cooling within the ordinary vapor space of the still tosuch cooling after said' vapors leave said vapor space and to suchcontact of the so cooled vapors with retrograding condensate thatpractically all of the gummy orasphaltic content of said vapors is con-.densed and that there is left a residue of uncondensed vaporspractically free from gummy or asphaltic matters and consisting -mainlyof lubricant (orlubricant andwax yielding) hydrocarbons, withdrawing theV gummy or asphaltic condensate, cooling said residual vapors to effecta condensation of condensate practically free from gummy or asphalticmatters and having a lubricant (or lubricant and wax yielding)character,

' and so continuing until a quantity of heayy 40 end distillate equal toabout half of the distillable portion of said-heavy end as a minimum hasbeen collected, substantially as described. K 2. The process ofdistilling petroleum in a form which contains the defined lubricant (orlubricant and'wax yielding) fraction of I or asphaltic content of saidvapors is 0011-.

V densed and that there is left a residue of uncondensed vaporspractically free from gummy orasphaltic matters and consisting mainly oflubricant (or lubricant andrwax yielding) hydrocarbons, withdrawing thegummy or asphaltic condensate, cooling said residual vapors t0efiect'aicondensation of were originally, first and jointly invented asthem, .drawing off as distillate so formed.

subjectin heavy en 7 and protected against undue coola formwhichcontains the defined lubricant (or lubricant and wax yielding) fractionofthe crude petroleum, by heating such undistilled petroleum (eventuallyat least) to the high temperatures (above 650 F.) necessary to distilthe, heavy end of said fraction, subjecting the vapors evolved from saidheavy end and protected against undue cooling within the ordinary vaporspace of the still to such cooling after said vapors leave said vaporspace and to such contact 96 of the so cooled vapors with retrogradingcondensate that practically all of the gummy or asphaltic content ofsaid vapors is condensed and that there is left a residue of uncondensedvapors practically free from gummy or asphaltic matters and consistingmainly'of lubricant (or lubricant and wax yielding) hydrocarbons,returning said gummy or asphaltic condensate to the oil. in

distillation, cooling said residual vapors to oo effect a condensationof them, drawing of? as distillate so formed condensate practically freefrom gummy or asphaltic matters and having a lubricant (or lubricant andwax yielding) character, and so continuing until a quantity of heavy enddistillate equal to about half of the distillable portion of said heavyend as a-minimum has been collected, substantially as described.

4g. The process of distilling petroleum in a fprm which contains thedefined lubricant (or' lubricant and wax yielding) fraction of the crudepetroleum, by heating such undistilled' petroleum (eventually at least)to the high temperatursf(ab0ve'650 F.) necessary to distil the heavy endof said fraction, V

thevapors evolvedffrom said in within the ordinary vapor space of thestrl to such cooling after said vapors leave said vapor space andtolsuchcontact of theso cooled vap orsiwith retrograding :conden jsatethatpractically all of; the'gummyor asphaltic content of said vaporsis condensed and that there is left alresidue or uncondensed'vaporspractically free from gummy or asphaltic matters and consisting mainlyof lubricant (or lubricant and waxy1elding) hydrocarbons withdrawing thegummy'or asphaltic condensate, cooling said Amie residual vapors toefiect a condensation 'oi them, drawing'ofi as distillate so formedlcondensate practically free from gummy or lubricant and wax yielding),character, and

asphaltic matters and having a lubricant (or so.cont'inuing until aquantit of heavy end distillate equal to about hal of the distillableportion of said heavy end as a minimum has been collected, thedistillation of said heavy'end being carried on at least eventually withcollection as distillate of mmy or asphaltic condensate, substantiallyas described.

so cooled vapors with retrograding condensate that practically all ofthe gummy or asphaltic content of said vapors is condensed or asphalticcondensate, ,coolingsai and that there is left a residue of uncondensedvapors practically free from gummy or asphaltic matters and consistingmainly of lubricant (or lubricant and wax yielding) hydrocarbons,withdrawing the (gummy residual vapors to effect a condensation of them,drawing oil as distillate so formed condensate practically free fromgummy or asphaltic matters and having a lubrlcant (or lubricant and waxyielding) character, and so continuing until a quantity of heavy enddistillate equal to about half of the distillable portion of said heavyend as a minimum has been collected, the distillation. of said heavy endbeing carried on at leasteventually with collection as distillate ofgummy or asphaltic condensate through draw ofls respectively of lowerand of higher temperatures, substantially as described.

6. The process of distilling petroleum in a form which contains thedefined lubricant (or lubricant and wax yielding) fraction of the crudepetroleum, by heating such undistilled petroleum (eventually at least)to the high temperatures (above 650 F.) necessary to distil first thelighter end and afterward the heavy end of said fraction, subjecting thevapors evolved from said lighter end and protected against undue coolingwithin the ordinary vapor space of the still to such cooling after theyleave said vapor space as to effect a condensation of said vapors.drawing oil so formed condensate as distillate, subjecting the vaporsevolved from said heavy end and protected against undra cooling withinthe ordinary vapor vapors leave said vapor space and to such contact ofthe so cooled vapors with retro-J grading condensate thatpractically allof the gummy or asphaltic content of said vaporsis condensed and thatthere is left a residue of uncondensed vapors practically free fromgummy or asphaltic matters and consisting mainly of lubricant (orlubricant and wax yielding) hydrocarbons, returning the gummy orasphaltic condensate to the oil in distillation, cooling said residualvapors to effect acondensation of them, drawing oii as distillateso'formed condensate practically free from gummy or asphaltic mattersand havin a lubricant (or lubricant and wax yielding character, and so011- tinuing until a quantity of heavy end distillate equal to abouthalf of the distillable portion of said heavy end as a minimum has beencollected, the lighter end condensate which is drawn OK as distillatebeing formed from vapors which pass over to be so condensed before theyhave been cooled even approximately to the extent to which said heavyend vapors are cooled in order to form the gummy' or asphalticcondensate which is returned to the oil in distillation, substantiallyas described.

7. The process of distilling petroleum in a form vwhich contains thedefined lubricant (or lubricant and wax yielding) fraction of the crudepetroleum, by heating such undis- ,tilled petroleum (eventually atleast) to the high temperatures (above 650 F.) necessary to distil firstthe lighter end and afterward the heavy end of said fraction, subjectingthe vapors evolved from said lighter end and protected against unduecooling within the ordinary vapor space of the still to cooling by meansof three successive sets of cooling devices after said vapors leavespace of thestill to such cooling after said ioo said vapor space and tocontact with the un1tedretrograding condensates: from the w first two ofsaid coolings, drawing off said united condensates as a distillate andcon densate' from the third of said coolings as a distinct distillate,subjecting the vapors evolved from said heavy end and protected againstundue cooling within theordinary vapor space ofthe still to cooling bymeans of the same successive sets of coo-ling devices to which saidlighter end vaporswere subjected and to contact with etrogradingcondensate from the first of siid coolings, withdrawing the three heavyend condensates separately, those from t'hesecond and third coolingsbeing drawn off as distinct. distillates, and so continuing untilquantities of heavy end distillates equal together to about-half of thedistillable portion of said heavy end as a minimum have beencollected.the first of said coolings of the heavy end vapors and the-contact of,the so cooled vaporswith retrograding condensate being vaporspractically free from gummy or assary to distil first'the lighter endand after- I ward the heavy end of saidfraction, subretrogradingcondensate being such that 'heavy end condensates separately, thoseminimum have been collected, the first of a residue is left ofuncondensed vaporspracheating petroleum in a form-that containsthedefined lubricant (or lubricant and wax such that practically all ofthe gummy or asphaltic contact of said vapors is condensed and that aresidueis left of uncondensed phaltic matters and consisting mainly oflubricant (or lubricant and wax yielding) hydrocarbons, substantially asdescribed.

8. The process of distilling petroleum in a formwhich contains thedefined lubricant (or lubricant and wax yielding) fraction of the crudepetroleum, by heating such undistilled petroleum (eventually at least)to the high temperatures (above 650 F.) necescondensates flow over saidbattles in contact with said vapors, drawing ofi said united condensatesas a distillate and the conden sate from the third of said coolings as adis- 1 tinct distillate, subjecting the vapors evolved from saidheavyend and protected against undue cooling within the ordinary vaporspace of the still to cooling by means of the same successive sets ofcooling devices towhich said lighter end vapors were subjected and tocontact withretrograding condensate from the first of said coolings inpassing over said bafiles, withdrawing the three from the second andthird coolings being drawn oil as distinct distillates, {LIId'SOcontinuing until quantities of heavy end dis tillates equal together :toabout half of the distillable portion of said heavy end as a saidcoolings of the heavy end vapors and the contact of the so cooled vaporswith practically all of the gummy or asphaltic content of said vapors iscondensed and that tically free from gummy or asphaltic matters andconsisting mainly of lubricant 1 (or lubricant and'wax yielding)hydrocarbons,

substantially asdescribed.

9. Apparatus for distilling petroleum, consisting of a still which isdesigned for yielding) fraction ofcrude petroleum (eventually at least)to the high tempera tures (above 650 F.) necessary to distil the heavyend of said fraction and which is arranged to protect the. evolvedvapors against undue cooling within the ordinary vapor space of saidstill, condensing means arranged to subject the passing vapors to suchcooling and to such contact with retrograding-condensate that inthe'distillation of said heavyend practically all of the ac-' companyinggummy or asphaltic matters can be separated thereby from uncondensedvapors representing about half of thedistillable portion of said heavyend as a minimum and consisting mainly of lubricant (or lubricant andwax yielding) hydrocarbons, additional condensing means, connections forconveying vapors from the ordinary vapor space of the still to the firstmentioned condensing means and from the lat ter to said additionalcondensing means, appliances for withdrawing condensate formed by thefirst mentioned condensing means, and a distillate draw-oil leading fromsaid additional condensing means and arranged to keep the distillateconveyed thereby distinct from the condensate withdrawn by saidappliances from the first mentioned condensing means, substantially asdescribed.

10 Apparatus for distilling petroleum, cc-ns1st1ng of a still which'isdesigned for heating petroleum in a form that contains the definedlubricant (or lubricant and wax yielding) fraction of crudepetroleum(eventually at least) to the high temperatures (above 650 F.)necessary'to distil the heavy end of said fraction and. which isarranged to protect the evolved vapors 7 against undue coolingwithin-the ordinary vapor space of said still, condensing meansarranged-to sub ect the passing vapors to such cooling and to suchcontact with retrograding condensate that in the distillation of saidheavy end practically all of the accompanying gummy or asphaltic matterscan be separated thereby from uncondensed vapors representing abouthalfof the distillable portion of said heavy end as a minimumandiconsisting mainly of lubricant (or lubricant and wax yielding)hydrocarbons, additional condensing means arranged to effectacondensation vof vapors first at higher and then at lower temperaturesand thus to form condensates of respectively heavier and lighter gravities, connections for conveying vapors from the ordinary 'vapor space ofthe still to the first men- 'tioned condensingimeansand from the latterto said additional condensing means,

appliances for wi thdrawing condensate formed by the first mentionedcondensing means, and distillate draw ofi's leading from difierent'partsof said additional condensing means and arranged to keep the respectivedistillates conveyed thereby distinct from each other and from thecondensate withdrawn. by said appliances from the first mentionedcondensing means, substantially as described.

11. Apparatus for distilling petroleum, consisting of a still which isdesigned for heating petroleum in a form that contains the definedlubricant (or lubricant and wax yielding) fraction of crude petroleum(eventually at least) to the high temperatures (above 650 F.) necessaryto distil the heavy end of said fraction and which is arranged toprotect the evolved vapors against undue cooling within the ordinaryvapor space of said still, condensing means arranged to subject thepassing vapors to such'cooling and to such contact with retrogradingcondensate that in the distillation of said heavy end practically all ofthe accompanying gummy or asphaltic matters can be separated therebyfrom uncondensed vapors representing about half of the distillableportion of said heavy end as a minimum and consisting mainly oflubricant (or lubricant and wax yielding) hydrocarbons, additionalcondensing means, connections for conveying vapors from the. ordinaryvapor space of the still to the first mentioned condensing means andfrom the latter to said additional condensing means, appliances forreturning condensate formed by the first mentioned condensing means tothe oil in distillation, and a distillate draw ofl leading from saidadditional condensing means, substantially as described.

12. Apparatus for distilling petroleum, consisting of a still which isdesigned for heating petroleum in a form that contains the definedlubricant (or lubricant and wax yielding-)- fraction of crude petroleumeventually at least) to the high temperatures (above 650 necessary todistil the heavy end of said fraction and which is arranged to protectthe evolved vapors against undue cooling within the ordinary vapor spaceof said still, condensing means arranged to subject the passing vaporsto such cooling and to such contact with retrograding condensate that inthe distillation of said heavy end practically all of the accompanyinggummy or asphaltic matters can be separated thereby from uncondensedvapors representing about half of the distillable portion of said heavyend as a minimum and consisting mainly of lubricant (or lubricant andwax yielding) hydrocarbons, additional condensing means, connections forconveying vapors from the ordi-- nary vapor space of the still to thefirst mentioned condensing means and from the latter to said additionalcondensing means, appliances for withdrawing condensate formed by thefirst mentioned condensing means, and a distillate draw ofl leading fromsaid additional condensing means and arranged to keep the distillateconveyed thereby distinct from the condensate withdrawn by saidappliances from the first mentioned condensing means, said apparatusincluding a distillate draw oli'ileading from the first mentionedcondensing means, substantially as described.

18. Apparatus for distilling petroleum, consisting of a still which isdesigned for heating petroleum in a form that contains the definedlubricant (or lubricant and wax yielding) fraction of crude petroleum(eventually at least) to the high temperatures (above 650 F.) necessaryto distil the heavy end of said fraction and which is arranged toprotect the evolved vapors against undue cooling within the ordinaryvapor space of said still, condensing means arranged to and to suchcontact with retrograding condensate that in the distillation of saidheavy end practically all of the accompanying gummy or asphaltic matterscan be separated thereby from uncondensed vapors representing about halfof the distillable portion of said heavy end as a minimum and consistingmainly of lubricant (or lubricant and wax yielding) hydrocarbons,additional condensing means, connections for conveying vapors from theordinary vapor space of the still to the first mentioned condensingmeans and from the latter to said additional condensing means,appliances for withdrawing condensate formed by the first mentionedcondensing means, and a distillate draw ofi leading from said additionalcondensing means and arranged to keep the distillate conveyed distinctfrom the condensate withdrawn by said appliances from the firstmentioned condensing means, said apparatus including distillate drawoils leading from the first mentioned condensing means and arranged tobe maintained at higher and at lower temperatures respectively,substantially as described.

14. Apparatus for distilling petroleum, consisting of a still which isdesigned for heating petroleum in a form that contains the definedlubricant (or lubricant and wax yielding) fraction of crude pertoleum(eventually at least) to the high tempera tures (above 650 F.) necessaryto distil the heavy end of said fraction and which is arranged toprotect the evolved vapors against undue cooling within the ordinaryvapor space of said still, condensing means arranged to subject thepassing vapors to such cooling and to such contact with retrogradingcondensate that in the distillation of said heavy end practically all ofthe accompanying gummy or asphaltic matters can be separated therebyfromuncondensed vapors representing about half of the distillableportion of said heavy end as a minimum and consisting mainly. oflubricant (or lubricant and wax yielding) hydrocarbons, ad-

subject the passing vapors to such cooling densing means and from thelatter to said additional condensing means, appliances for returningcondensate formed by the first mentioned condensing means to the oil indistillation, a distillate draw off leading from the first mentionedcondensing means, and a distillate draw off leading from said additionalcondensing means, substantially as described.

15. Apparatus for distilling petroleum, consisting of a still which isdesigned for heating petroleum in a form that contains the definedlubricant (or lubricant and wax yielding) fraction of crude petroleum(even-' itually at least) to the high temperatures (above 650 E)necessary to distil the heavy end of said fraction and which is arrangedto protect the evolved vapors against undue cooling within the ordinaryvapor space of said still, condensing means which include threesuccessive sets of cooling devices connected in series for passage ofthe residual vapors from'each preceding to the following set of coolingdevices and adapted the first set for bringing the passing vapors intocontact with retrograding condensate and the second set for delivery ofcondensate therefrom to the'upper part of the first set, connections forconveying vapors from the ordinary vapor space of the still to the firstof said sets, separate distillate draw ofis leading from the second andthird of said sets respectively, and appliances for withdrawingcondensate from the first of said sets, which appliances include adistillate draw 01f leading from the first of said sets, the first ofsaid sets being arranged to subject the passing vapors to such coolingand to such contact with retrograding condensate that in thedistillation of said heavy end practically all of the accompanying gummyor asphaltic matters can be separated thereby from uncondensed vaporsrepresenting about half of the distillable portion of said heavy end asa minimum and consisting mainly of lubricant (or lubricant and waxyielding) hydrocarbons, substantially as described.

16. Apparatus for distilling petroleum, consisting of a still which isdesigned for heating petroleum in a form that contains the definedlubricant (or lubricant and wax yielding) fraction of crude petroleum(eventually at least) to the high temperatures (above 650 necessary todistil the heavy end of said fraction and which is arranged to protectthe evolved vapors against undue cooling within the ordinary vapor spaceof said still, condensing means which include (first) a set of coolingdevices whereof a chamber with baflies therein for bringing the passingvapors into contact with retrograding condensate forms part, and(second) a set of cooling devices whereby the vapors are passed insubdivided streams between closely approached heat removing surfaces,and (third) another set of cooling devices, the three sets of coolingdevices being connected in series for the passage of the residual vaporsfrom each preceding to the following set of cooling devices and thesecond mentioned set of said cooling devices being adapted for deliveryof condensate therefrom to the upper part of said chamber, connectionsfor conveying vapors from the ordinary vapor space of the still to thefirst mentioned set of cooling devices, separate distillate draw oifsleading fromthe second and third of said sets respectively, andappliances for withdrawing condensate from the first of said sets, whichappliances include a distillate draw ofi' leading from the first of saidsets, the first of said setsbeing arranged to subject the passing vaporsto such cooling and to such contact with retrograding condensate that inthe distillation of said heavy end practically all of theaccompanyinggummy or asphaltic matters can be separated there- WILLIAM C. KOEHLER.LUDWIG LINK.

\Vitnes ses:

CHARLES G. BLACK, GEO. W. Gonnon.

